Jawless vertebrates are members of

Options

A. Agnatha
B. Cephalochordata
C. Gnathostomata
D. Urochordata

Answer

**Step-by-Step Solution:**

1. **Understanding Vertebrates**: Vertebrates are classified under the subphylum Vertebrata, which is part of the phylum Chordata. This classification is essential to understand the broader context of jawless vertebrates.

2. **Divisions of Vertebrates**: The subphylum Vertebrata is divided into two main groups: Agnatha and Gnathostomata.
- **Agnatha**: This group consists of jawless vertebrates.
- **Gnathostomata**: This group includes vertebrates that possess jaws.

3. **Identifying Jawless Vertebrates**: Within the Agnatha group, there are two primary examples of jawless vertebrates:
- **Lampreys**: These are parasitic fish that attach to other fish and feed on their blood.
- **Hagfish**: These are scavengers that feed on dead or dying fish.

4. **Characteristics of Agnatha**: Members of Agnatha have a round, circular mouth that is muscular and lacks any bony structure. This distinguishes them from jawed vertebrates.

5. **Conclusion**: Based on the classification and characteristics discussed, jawless vertebrates are classified under the group **Agnatha**.

**Final Answer**: Jawless vertebrates are members of **Agnatha**.

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